An open label, prospective, randomized cross-over phase II study in up to 60 sickle cell patients who are either homozygous for Hb S or have HbSB0 thalassemia. Initially, each patient will be treated for 6 weeks with placebo or a standard dose of propranolol (40 mg) every 12 hrs. This will be followed by a 2-week washout period after which, patients will receive the other treatment modality (placebo or propranolol).

We Hypothesize that propranolol administered in vivo on a daily basis for 6 weeks (1) will decrease baseline adhesion to endothelial cells and will substantially abrogate epinephrine-stimulated adhesion to endothelial cells, as measured in vitro; (2) will improve biomarkers of endothelial activation and dysfunction; and (3) can be safely used in patients with SCD. Thus, the use of propranolol in SCD may represent a safe and effective means of anti-adhesive therapy in SCD.

Study Objectives:

Primary Objective:

• To establish the safety and efficacy of long-term therapy with propranolol as an anti-adhesive therapy for SCD.

Secondary Objective:

• To evaluate changes in soluble markers of endothelial activation and dysfunction.

Correlative Science Objective:

• To determine whether response to propranolol therapy is associated with polymorphisms in genes encoding the proteins involved in the upregulation of Sickle Red Blood Cell (SS RBC) adhesion by epinephrine.

The stickiness of SS RBC will be evaluated by a well-established in vitro assay of adhesion of SS RBCs to cultured endothelial cells using a flow chamber. Overall change of adhesion from baseline to post intervention( Week 0 to 6 and week 8 to 14) in unstimulated cells (Sham treated) vs. Stimulated Red Blood Cells (Epi-treated) at 1 dyne/cm2

The stickiness of SS RBC will be evaluated by a well-established in vitro assay of adhesion of SS RBCs to cultured endothelial cells using a flow chamber. Overall change of adhesion from baseline to post intervention( Week 0 to 6 and week 8 to 14) in unstimulated cells (Sham treated) vs. Stimulated Red Blood Cells (Epi-treated) at 2 dyne/cm2

The stickiness of SS RBC will be evaluated by a well-established in vitro assay of adhesion of SS RBCs to cultured endothelial cells using a flow chamber. Overall change of adhesion from baseline to post intervention( Week 0 to 6 and week 8 to 14) in unstimulated cells (Sham treated) vs. Stimulated Red Blood Cells (Epi-treated) at 3 dyne/cm2

Biomarkers of Endothelial Activation and Dysfunction: Overall change of Plasma levels of sE-selectin measured in triplicate on plasma samples using commercially available ELISA kits from baseline to post intervention ( Week 0 to 6 and week 8 to 14).

Biomarkers of Endothelial Activation and Dysfunction: Overall change of Plasma levels of sP-selectin measured in triplicate on plasma samples using commercially available ELISA kits from baseline to post intervention ( Week 0 to 6 and weeks 8 to 14).

Biomarkers of Endothelial Activation and Dysfunction: Overall change of Plasma levels of sICAM-1 measured in triplicate on plasma samples using commercially available ELISA kits from baseline to post intervention ( Week 0 to 6 and week 8 to 14)

Biomarkers of Endothelial Activation and Dysfunction: Overall change of Plasma levels of sVCAM-1 measured in triplicate on plasma samples using commercially available ELISA kits from baseline to post intervention ( Week 0 to 6 or week 8 to 14)

Treatment will be with a standard propranolol dose of 40 mg every 12 hrs.Each patient will participate in 6 weeks of treatment with placebo or study drug (propranolol), followed by a 2-week wash-out period and then 6 weeks of treatment with the other modality (placebo or propranolol).

Placebo Comparator: Sugar pill

Placebo arm

Drug: Placebo

Treatment will be with a standard propranolol dose of 40 mg every 12 hrs.Each patient will participate in 6 weeks of treatment with placebo or study drug (propranolol), followed by a 2-week wash-out period and then 6 weeks of treatment with the other modality (placebo or propranolol).

Eligibility

Ages Eligible for Study:

18 Years and older

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Diagnosis by electrophoresis (HEP) of Hemoglobin (Hgb) SS or Hgb Sβ0 thalassemia (all patients followed at our clinic have HEP-confirmed diagnosis on file)

Use during the screening or study period of any of the following medications: antihypertensives, diuretics, thyroid replacement therapy, anti-arrhythmia medications, bronchodilators, inhaled steroids, insulin, or hypoglycemic medication

History of allergy to sulfonamides

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT01077921